Improvement in graduating levels



N. HOLLINGSWORTH;

Graduating Leveif a N0. 66,342 V I Patented July 2, 1867.

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IMPROVEMENT IN GRADUATING LEVELS.

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TO ALL WHOM IT MAY CONCERN:

Be it known that I, N. HOLLINGSWORTH, of Rosetta, county of Hendersondstate' of Illinois. have invented a new and improved Graduating Level; and I do hereby declare that the following is a full, clear, and exact description thereof, which will enable others skilled in the art'to make and use the same, reference being bad to the accompanying drawing, forming part of this specification, in which Figure 1 represents a sectional side elevation of this invention.

Figure 2 is a transverse section of the same.

Figure 3 is a plan or top view of the same.

Similar letters of reference indicate like parts.

This invention relates to a levelling instrument, which is provided with a telescope, a needle-box, and adjusting springs in such a manner that, by means of the needle in the needle-berg, the indication of the telescope or its position toward the horizon can be determined at a glance; and furthermore, the telescope, when adjusted in a horizontal position, can be locked so that it ca n'be made to swivel in a horizontal plane without being permitted to deviate from its horizontal position. If the telescope is released it can be readily adjusted to any desired indication, and an instrument is obtained which can be used with advantage in cross-leveling and in surveying operations of any description. i p

A. represents a telescope, which is rigidly attached to the needle-box B, and this needle-box is provided with two gudgeons a, which have their bearings in standards I1, so that thetelescope can be brought in a horizontal or in an inclined position, as may be desirable. The standards 6 rise from a disk, 0, which turns freely on a central pivot, a, that is secured in the bed-plate D, and this bed-plate is supported by the three-legged stand E, and provided-with four (more or lesslset-screws (i, so that its position can be adjusted after the stand has been put up in the desired locality. Suitable friction-springs e, secured to the inner surface oi the standards b, and bearing on the heads of the needle-box, prevent the telescope from oscillating on its gudgeons spontaneously, and a pinion, f, which gears into a toothedsegment, 9, attached to one of the heads of the needlebox, serves to adjust the telescope in the requisite position in relation to the horizon. The pinionfis mounted on an axle, h, which has its hearings in a suitable box attached to the disk 0 and in one of the standards 6, and a button, 2', secured ,to its outer end, serves to turn said axle and pinion; On the upper surfaceof the disk 0 a spring, j, is secured, the end of which projects through an L-shaped slot in meet the standards 6 next to the button 1'. From said spring projects a stud, k, and if the outer end of the spring is brought into the-vertical part of the L-shaped slot, this stud is permit-ted to drop into a recess in the circumference of the needle-box, and thereby a positive stop is obtained for the telescope, so that the same is not allowed to leave its position spontaneously. If the telescope is adjusted in a horizontal plane by the set-screws d, it can be freely turned in either direction without danger of losing its horizontal position, which is of great value in cross-levelling. If it is desired to bring the telescope in an inclined position, the spring catch 3' 7c is depressed and its outer end is turned into the horizontal portion of the L-shaped slot, thus i elieving the needle-box and allowing it to turn up or down in either direction. In the centre of the circular needle-box B there is an axis or arbor passing across the box, withits pivots in the same range of centres on which the telescope and needle hox turn,'from which axis there are two arms or needles extending upward, passing one on each side of the telescope, the

upper ends or points of which are connected with each other by a very fine wire, it, drawn. tightly from one point to the other across the top of the telescope, and passes over a circular scale, P, which scale is divided into degrees, beginning at the top centre of the curved scale, and numbering down each way to forty-five degrees, over which scale the fine cross-wire traverses freely, with a circular motion, from one extremity of the scale to the other; and by a small adjustable weight, 0, attached to the lower ends of the needles, and nicely balanced compel the needles to seek a perpendicular position, which shows very accurately the angle at all times of the telescope to the plane of the horizon. This arrangement is all encased in the circular fneedle box B, and over the scale and index thereis placed a small section of curved glass, to protect it from all extraneous influences. The oscillations of the index on the scale can be arrested at any moment by means of a brake, g, the outer end of which projects under the small end of the telescope; and by depressing said end the brake is applied to the arbor Z, and the index is compelled to find its state of rest in a short time. An'instrument is thus obtained which is simple in its construction and very convenient for surveying in all its branches What I claim as new, and desire to secure by Letters Patent, is

The weighted arbor Z and arms m, withindex a, traversing over the scale 19, in combination withvthe telescope A and brake g, constructed and operating substantially as and for the purpose described.

NATHAN HoLLINGsWonTH.

Witnesses:

G. W. Lorrrus, Jossrn SALMON. 

